|Speciale, 3. modul, 2006, id:257|
|Findes på RUb:||ja|
The purpose of this master thesis has been to determine whether Electrical Impedans Spectroscopy can be used for determination of the electrical characteristics of deep states in semiconductors. A test sample of silicon was bombarded with 2 MeV electrons, creating a number of defects with energy levels within the forbiddeen energy gap. This sample was measured using DLTS as a reference in order to be able to compare the results from the EIS measurements and analysis. The necessary semiconductor theory is reviewed and the principles behind creating a reticulated R, C electrical equivalent network model are described. The results from this project show that the EIS method is capable of determining the characteristics of the deep states, provided the density of these is relatively high. At low densities, the method fails, at least with the suggested model. The development work related to the experimental setup, consisting of a 0.001Hz to 1kHz, and 40Hz to 110MHz impedance analyzers, a cryostat covering the temperature range of 90 degrees K and a specialized sample holder are also described.